Elastic compression stockings have long been used for the treatment of chronic venous insufficiency (CVI). Generally, such "anti-embolism" stockings extend over the wearer's leg and foot and are adapted to exhibit a controlled, gradient compressive force on the leg. Typically, the compressive force is greatest at the ankle area and diminished over the length of the stocking to a minimum at the top. Examples of such compression hosiery are disclosed in, for example, U.S. Pat. Nos.: 4,172,456; 4,502,301; 4,513,740; 2,574,873 and 2,816,361.
CVI is defined as any abnormality of the peripheral venous system that reduces or restricts venous return, thereby causing blood pooling and increased venous pressure. Patients exhibiting such blood pooling and increased venous pressure are at increased risk for developing blood clots in their legs, with the attendant risk of the clots breaking loose and traveling through the venous circulation back to the heart and into the lungs, thus leading to a potentially fatal pulmonary embolism. CVI includes a spectrum of circulatory problems, including vein competency, patency and wall properties, as well as extravascular factors. These extravascular factors include the muscle pumps of the foot, calf and thigh which are in turn dependent on proper neuromuscular function and mobility of the joints (particularly the ankle) and connective tissue support by fascia.
The spectrum of symptoms attributed to those afflicted with CVI includes lower leg extremity pain, itching, burning, fatigue, cramps, swelling, and in advanced stages, ulceration of the lower leg. Gradient compression of the leg is highly effective in reducing lower extremity venous pressure and venous pooling. This enables the calf muscle pump to increase venous return. Thus, CVI patients undergoing compression hose therapy are usually relieved of nearly all symptoms, including ulceration.
While gradient compression stockings are in widespread use for the treatment of CVI, they have not heretofore generally been used by those who are free of this disease. Because they are restricted to medical applications, the compression hosiery are usually physician prescribed or are available over the counter upon the recommendations of a physician.
Aerobic type exercise is increasingly becoming a part of the normal fitness regime. The benefits of such exercise need not be discussed in detail here, but include reduced incidence of coronary disease, greater stamina and strength, increased energy levels, increased longevity, etc. Thus, a large number of healthy adults engage in such aerobic exercise on a regular basis.
While undoubtedly beneficial, aerobic exercise and other athletic activities involving the strenuous use of the lower extremities carry certain risks. In particular, the lower leg, ankle, and foot include a number of intricate intrinsic muscle and joint complexes. Instability of the foot and ankle joint complexes resulting from excessive pronation and supination, with added impact trauma to the lower leg, has been associated with a number of overuse injuries. These injuries include Achilles tendinitis, peroneal tendinitis, and plantar fasciitis. The motion of pronation is characterized by inward rotation of the lower leg upon the foot causing the arches to flatten out. Supination involves an outward rotation of the lower leg resulting in high arches in the foot.
Conventional methods of stabilizing the foot and reducing trauma to the lower leg include arch supports, specially designed athletic shoes such as high top basketball shoes, and various athletic training taping procedures. U.S. Pat. No. 5,263,923, for example, discloses a wearing article including highly stretchable portions which extend along the muscle groups of a body portion in order to simulate a "taping" function. These prior art methods have all produced somewhat limited benefits.
Thus, both "weekend" and serious athletes could benefit from increased protection of these intricate muscle and joint complexes. Furthermore, increased blood flow through the lower extremities could well give these athletes a "boost" in performance, as well as reducing fatigue and pain caused by build up of lactic acid within the muscles, as well as reducing the likelihood of developing CVI.
Thus, what is needed is a device which both enhances the performance of casual and serious athletes in an easy to use and nonintrusive manner, and which also provides the added benefit of protecting the user from injury and disease.